[Shane@DBPerformance]

I would do the 2G MAF and EPROM. I do custom chip tunes on 1Gs with just an EPROM ECU. It's a lot better than the SAFC route. Running 650cc injectors with an AFC and 2G MAF will cause the ECU to want to run a lot of timing at pump gas airflow levels. Even though doing a 2G MAF with 550s almost evens out, all it is doing is reporting less airflow to the ECU, which is just like doing it with the SAFC itself. Running 650s on a 1G DSM without changing the injector scaler in the ECU will require lowering the airflow reported to the ECU by 30+%, which can cause problems on some cars that aren't exceeding the top airflow row of the timing map by that same 30+%.

You could do a generic chip in an EPROM ECU setup for your injector size/2G MAF and then fine tune it with the SAFC also. Then atleast you would be closer to start with and not have to go as far negative on the SAFC.